Mahakali literally translated as Great Kali, is a Hindu Goddess, considered by some to be the consort of Shiva, and by others as the basis of Reality (see below). Mahakali in Sanskrit is etymologically the feminized variant of Mahakala or Great Time (which is interpreted also as Death), an epithet of the God Shiva in Hinduism. Mahakali is another name of the dark Goddess Kali, who is the force of the anger of Durga and is an aspect of the Mahashakti and therefore her color is light blue. She is believed to be the greatest aspect of Kali whom many Hindus hold as a Divine Mother.

Mahakali (Kali Devi) is one of the incarnations of 'Shakti' of Durga. She is the power bestower and is believed by Hindus to be the destroyer of evils and enemies. This form of Durga is most adored in Bengal and Bihar. She is also called Mahishasur Mardini (The destroyer of Demon Mahishasur who was a frightening figure on earth at a time). Kali or Mahakali is specially adored during both the Navratras by the Hindus.

Mahakali's mythology is contained in various Puranic and Tantric Hindu Scriptures (Shastra), where She is variously portrayed as the Adi-Shakti or Primeval Force of the Universe, identical with the Ultimate Reality or Brahman, the (female) Prakriti or World as opposed to the (male) Purusha or Consciousness, or as one of three manifestations of Mahadevi (The Great Goddess) that represent the three Gunas or attributes in Samkhya philosophy; in this interpretation Mahakali represents Tamas or the force of inertia. A common understanding of the Durga Saptashati or Chandi Path (the Devi Mahatmya or "Greatness of the Goddess", a later interpolation into the Markandeya Purana, considered a core text of Shaktism, the branch of Hinduism which considers Devi to be the highest aspect of Godhead) assigns a different form of the Goddess (Mahasaraswati, Mahalakshmi, and Mahakali) to each of the three episodes therein.